This thread was down for ages because my college web space where I hosted the images expired and I had forgotten that's where I kept the images. A double hard drive failure in 2011 led to many lost photos and a complete loss of photo organization (people, use online backup services, seriously). Anyway, the photos are back!

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Now that many of the early spring amphibians have ended their migrations to wetlands, bred, and in many cases moved back uphill, the time has come to get into the field and keep track of egg masses.This time of year up until about the end of May (this far north anyway) there are only a handful of mass-laying species we have to worry about:

In this post I will not be dealing with mid-summer breeders such as Bullfrogs and Green Frogs, or species that do not lay noticeable egg masses such as Eastern Newts, Blue-spotted Salamanders, or Spring Peepers, etc, which all lay individual eggs or groups of 2-3 eggs attached under leaves and debris.Please note that old egg masses that have hatched out or are about to hatch may be tattered, torn, or completely separated into a film. First, I'll start by teaching you about the difference between frog and salamander eggs, then move on to identification of each species.

Frog vs. Salamander eggs

Let's start simple. Frog eggs vs. salamander eggs. Telling the difference between the two is quite easy. Frogs lay individual clear eggs with a visible embryo contained within each egg. With frogs, the outside edge of the egg mass is made up of the eggs themselves. Salamanders take it a step farther and coat the entire egg mass with an additional layer of jelly. These two photos demonstrate the difference clearly:

Frog eggs. You can easily see the contour of each individual egg on the outside of the mass.

Salamander eggs. Notice that there is a layer of gel surrounding the mass of eggs. This protective film around the egg mass is characteristic of all salamanders in the genus Ambystoma, which includes pretty much all the pond-breeding salamanders you're going to find the eggs of.

You can still see the outline of each egg within the mass if you look closely.

Again, frog = no gel surrounding entire mass, you can see the contour of each individual egg.

Salamander = layer of gel surrounding the entire egg mass.

And side by side:

This extra layer of gel around salamander egg masses is thought to provide the eggs some protection against predators such as the dreaded Eastern Newt, which apparently just eats its way past the gel anyway:

Now we'll go down the list of egg-mass laying species in Vermont one by one.

Wood Frog

Wood frog egg masses are pretty easy to identify. You would expect to find Wood Frogs breeding in ponds, vernal pools, and marsh edges in or near forested habitat at a wide range of elevations as soon as the snow melts and the ground thaws. A typical egg mass can have between 500 and 2000 eggs. The embryos start out black on top and white on the bottom, as do most open-water amphibian eggs, but as the embryo develops into a tadpole the white is lost. A fully-formed mass that has been in the water for a day or so is about the size of a softball and the clear space between the embryos and the margin of each egg is many times greater than the width of the embryo (see the first photo posted).

This, of course, is a much closer look than you'd normally get. Here's another example.

At a glance, Wood Frog egg masses underwater will look something like this:

Often, groups of Wood Frogs will lay their eggs in close proximity, usually on emergent vegetation or submerged tree branches:

Sometimes amphibian eggs can have an opaque hue to them. I am not sure what causes this in Wood Frogs although in Spotted Salamanders it is caused by the genetics of the female.

When wood frog eggs are laid, however, the masses are much more compact. Obviously a golf ball-sized frog isn't going to lay a softball-sized egg mass. Directly out of the frog an egg mass is smaller than a golf ball, but swells to full size within hours.

Northern Leopard Frog

Leopard Frog eggs look a lot like Wood Frog eggs with a couple key differences. The embryos are about the same size (2-3mm), but the eggs themselves are much smaller and tighter. The clear space between the margin of the eggs and the embryo is usually the about the same thickness as the embryo itself (remember, the clear space in a wood frog is much bigger). Because Leopard Frogs lay more eggs per mass than Wood Frogs (2000-4000), but the eggs are much smaller, the entire egg masses end up being about the same size (think baseball-softball).

Notice how tight the egg mass is? Wood frogs have much more clear space between the embryos. Here's a picture of an undisturbed Northern Leopard Frog egg mass.

Leopard Frogs typically lay their eggs in lake and river flood planes where sedimentation and silt can build up pretty quickly. Remember that Wood Frogs tend to breed in ponds and vernal pools. Sure, there is some overlap in breeding habitat between Leopard and Wood Frogs, but knowing the typical breeding habitat for each species can help in many cases.

Pickerel Frogs have very similar egg masses compared to Leopard Frogs, but look at how the Leopard Frog eggs are black on top and white on bottom. Pickerel Frog eggs are brown on top and yellow on the bottom. Other than that the eggs are pretty much the same.

Pickerel Frog

If you can identify Leopard Frog eggs you can identify Pickerel Frog eggs. The egg masses are almost exactly the same except instead of the eggs being black on top and white on bottom, Pickerel Frog eggs are brown on top and yellow on bottom. Pickerel Frogs are usually found higher in elevation than Leopard Frogs, usually found breeding in upland ponds or small lakes, compared to Northern Leopard Frogs which most often breed in lowland flood planes. Habitat counts!

You might read that Pickerel Frog egg masses are plinth-shaped. I didn't know what a plinth was and had to look it up. Other sources say the egg masses are spherical, which is more consistent with my observations. Anyway, for what it's worth, this is a plinth:

American Toad/Fowler's Toad

Where I live, the American Toad is the only frog that lays its eggs in a long string. A single strand could have between 2,000 and 20,000 eggs depending on the size of the female. Breeding occurs in the warmer months (mid-summer in Vermont). American Toads TEND to be found in hardwood forests with loamy soils. Fowler's Toads TEND to be found in coastal or flood plane habitat with sandy soils.

Once sediments settle on the strands actually recognizing them as eggs can be difficult to someone unfamiliar with them.

I've never seen Fowlers Toad eggs and don't know if there is a good way to tell them apart. At least I'm being honest. If you have photos or ID tips, post 'em! My understanding is that the eggs are indistinguishable from one another. Interestingly, these toads are the only frogs in the northeast that will sometimes lay eggs alongside flowing streams and you can often see schools of their tadpoles moving around in brooks, especially in the pools adjacent to brooks where the current is a little slower.

Spotted Salamander

Spotted Salamander egg masses are made up of about 50-250 eggs, can be as large as a grapefruit, and are very dense/firm. Usually they are laid in ponds, vernal pools, and marsh edges without fish, but you'll find them in pond with fish too. If you pick up a Spotted egg mass it will usually hold its shape in your hand. The eggs are usually attached to sticks, branches, and vegetation below the surface of the water.

Even as the egg mass ages and the embryos develop you can see that it is firm and continues to hold its shape when pulled from the water.

Just like Wood Frogs, you'll often fine huge numbers of egg masses all in one spot. Interestingly, some Spotted Salamander egg masses are a grayish opaque color. This is caused by a genetic trait of the mother and is common in some places.

And again, Spotted Salamander egg masses expand after being laid. Obviously the eggs don't take up the volume of a softball while still inside a hot dog-sized salamander.

Jefferson Salamander

Pure Jefferson Salamander eggs are laid in masses of 20-30 eggs but females usually lay multiple masses.Sometimes masses are laid in a line down a single stick and, once they swell with water, may fuse into one another and appear to make up a single mass.The masses closely-resemble those of Spotted Salamanders but, in addition to being much smaller, are not firm. If you pick up a Jefferson mass the eggs will run through your fingers or break off the stick before even making it into your hand.

In the above photos it almost looks like some of the eggs are about to fall right off the stick.

And here's a freshly-laid Jefferson Salamander egg mass next to the salamander who laid them:

Blue-spotted Salamander

Blue-spotted Salamanders do not lay egg masses. Their eggs are attached individually or in groups of two or three on the underside of leaves. Hardly anybody ever sees them, I don't have any photos of them, don't bother looking for them.

Jefferson/Blue-spotted Salamander hybrids

Hybrids between Jefferson and Blue-spotted Salamanders exist.The two pure species cannot breed with one another however a hybrid line of almost entirely parthenogenic females can breed with either pure species.It's a very complicated subject that I'd be happy to talk about in more detail another time. Hybrids more closely-related to Blue-spotted Salamanders will lay individual eggs or small clusters of eggs under leaf matter. Those closer to the Jefferson Salamanders will lay egg masses that basically look like those of pure Jefferson Salamanders.Hybrid egg masses, however, usually have a high proportion of nonviable eggs that do not develop. The dud eggs are usually gray and swell up quickly. The gray swelling is caused by the water mold saprolegnia. Saprolegnia can be seen in amphibian eggs of any kind but it is very common in Jeff/Blue-spotted hybrids.

Here is a good photo of a hybrid egg mass. Observe that a bunch of infertile (whitish) eggs are in the center of the mass. To be completely honest though, you can't say with 100% certainty this is a hybrid egg mass, but any egg mass that looks like it is from a Jefferson Salamander, is within a zone of hybridization, and has more then one or two infertile eggs should be considered most likely that of a hybrid salamander.

Bryozoans

These are not amphibian eggs. They are colonies of microscopic animals similar, but not related, to corals. They are firm, have these weird crusty things on the outside, and no embryos on the inside. People confuse them for amphibian eggs a lot, but now you know better.

That is all. Have fun herping! And remember to submit reports to your local herp atlas. For Vermont that would be this one: VT Reptile and Amphibian Atlas Project. Use google to find your own if you don't already know.

In addition to that, or if your state doesn't have a herp atlas, report your findings to Herp Mapper :)

Last edited by Gyri on April 4th, 2016, 7:31 pm, edited 12 times in total.

I really like the shot of the maculatum depositing eggs on the stem, very awesome. A thorough post indeed

I think there is a typo in the wood frog section, it says "between 500 and 200 eggs", guessing that should say 2000 eggs (though i'd be surprised if any got over 1,500). And with American toads, 5000 eggs would be low-ballin' it. I've counted almost 11,000 in one female.

I think there is a typo in the wood frog section, it says "between 500 and 200 eggs", guessing that should say 2000 eggs (though i'd be surprised if any got over 1,500). And with American toads, 5000 eggs would be low-ballin' it. I've counted almost 11,000 in one female.

Thanks for pointing those errors out. Wood Frogs were a typo, as you guessed. American Toads were just me being wrong. I've just hit the books, it's 2,000 - 20,000 eggs.

I am bumping this now that egg mass season has begun in parts or our region. I will add Tiger Salamanders to this writeup as soon as somebody tells me something useful about how to differentiate tigrinum eggs from maculatum eggs beyond a simple embryo count (too much overlap for my comfort). I would also need photos Kyle, Bob, or Nate, I recommend sticking this. Kyle mentioned he would do that when egg mass season returned way back when I first posted this pre-crash.

What's this one? Found in a shallow seep-pool in southeastern KY in May of last year. Notice the hemlock needles in the substrate for size reference. I didn't handle it so have no clue as to the consistency.

Haha, beats me. It does not look like a mass-laying species Kentucky is getting south enough that there are a lot of species who's eggs I'm not familiar with. Perhaps spinifer or someone else has a clue.

What's this one? Found in a shallow seep-pool in southeastern KY in May of last year. Notice the hemlock needles in the substrate for size reference. I didn't handle it so have no clue as to the consistency.

Was there are loose mass containing those eggs? I think they might be chorus frogs. The versicolor/chrysoscelis eggs I have found were freshly laid, but floating on the surface. Maybe they sink after they begin developing.

Yeah, I think there is potential for chorus frog masses in May but they should be getting hard to find by then. I don't have a lot of experience with chorus frogs but in the south my impression is that you can hear them calling just about any time of year but the peak is over in March with a little activity continuing into April. They hatch pretty quickly but it's certainly not out of the question for early May.

It was in early May. The site is in an old growth hemlock grove in a deep canyon - it stays pretty cool. I visited the site again in August and found several tadpoles, that I assume hatched from the egg mass. Pseudacris brachyphona:

This is perfectly perfect in every way. Thanks for taking the time to post the answers to exactly the questions that I was trying to answer with google searches for the past few days.

I'd still like to see examples of pure blue spotted and peeper eggs just for comparison if people have them!

Thanks again Gyri.

-Alex

Thanks. Peeper and blue-spotted eggs were not included because those two species lay their eggs singly or in very small groups on the undersides of leaves and attached to low-laying vegetation and it is very uncommon to actually find those since there are no actual masses. I have scooped up blue-spotted eggs a couple times by accident and have seen peepers lay eggs in captivity but have never taken photos of either. These days I always have my camera on hand so you can be sure I'll snap a shot if I find any in the future.

Ok guys, I am stumped, I have used this thread for a reference many times over and the other day I was out and could NOT figure out what this belongs to. Any ideas? A little background on the location.

This was in a mountain area, heavily forested, in a flooded area where there are many vernal pools. There were plenty of Ambystoma Maculatum masses, along with what appeared to be some frog species. This however was a small pool seperated from the others that was quickly drying out(I don't know if that had any effect on the way the eggs were position or not). I found some Eastern Spotted Newts in these pools along with hearing the occasional frog. I did not see any toads around that I recall.

This picture was taken around April 10th or 11th(I cannot recall) Sorry for the blurry-cam picture quality, I did not have my DSLR with me so my cell phone camera had to do.

I can't tell if the eggs are black and white and the photo is tinted yellow or if the eggs are actually brown and yellow. If the embryos were brown on top and yellow on bottom, as the photo appears, I would say those are pickerel frog eggs. If they were black on top and white on the bottom then leopard.

My guess is that the habitat was either permanent water or in a flood plane (not a woodland vernal pool)?

Cool. A permanent woodland pond sure fits the bill for pickerels too. If you read the description in some text books, pickerel frog egg masses are "plinth-shaped". I have yet to see one that is obviously plinth-shaped and also have yet to meet herpetologist who knew off the top of their head what a plinth is without having looked it up after reading about it in the frog description.

I heard the first pickerel frogs of the year calling up here in VT the other day. Now, if I can just find their eggs.

Oh man, Spadefeets, another I need to add. Would you guys say that spadefoot eggs generally look like jefferson masses but without the extra layer of protective jelly around the entire mass? It's not a species I've ever seen the eggs of.

I'm not very good at telling the difference between American and Fowler Toad. These were found in a small puddle/ditch in the middle of a dirt road with a vernal literally on either side of the road. These were the tightest corkscrews I've ever seen. The vernals already had hundreds of Anaxyrus larvae. So the question is, American or Fowler's?

Those eggs are screwy!Sorry for the late response here. I'm actually not sure if there is a good way to tell amercan from fowlers eggs. You'd probably need to make that call based on habitat and have some knowledge about the local distributions of the two species. MattJ might have more insight into this one, he's our toad guy

withalligators wrote:

Hey folks,Does anyone have any pictures of the eggs of some of our local hylid friends? Cheers,Alex

I don't have any, unfortunately. To my knowledge, none of our northeast treefrogs lay actual egg masses and instead lay eggs loose in vegetation. The only time I've ever seen treefrog eggs was as they were coming out of the treefrog. In that case it was not necessary to look closely at the eggs to know what species they had come from.

I know, but I'm in NY right now. When I get back to MD I'll try to get Vince to post the pictures he took of the mass if they are any good. I have pics of regular versicolor as well, but they are somewhere mysteriously elusive. I think it would be awesome to get this thread as complete as possible. Those cricket frog egg pics we got should go up here too.

I think it would be awesome to get this thread as complete as possible. Those cricket frog egg pics we got should go up here too.

I agree. I intended to update the thread with all the other mass-laying species early this spring but never got around to it. Life does weird things to me sometimes... This thread is the #1 result in google for the search term "Egg Mass ID". It got at least one new person to register on the forum (though they have not been back since). I'll definitely have it brought up to date before the next egg season. I will also edit the post to have more likely google search terms

I'm not very good at telling the difference between American and Fowler Toad. These were found in a small puddle/ditch in the middle of a dirt road with a vernal literally on either side of the road. These were the tightest corkscrews I've ever seen. The vernals already had hundreds of Anaxyrus larvae. So the question is, American or Fowler's?

A good clue in this is timing! American's breed much earlier in the year than Fowler's.

Also, STICKY FOR SPRING!

Last edited by John Vanek on April 13th, 2012, 6:44 pm, edited 1 time in total.